Table 2.
Sensitivity and specificity of the antigen detection test in the total sample and in different subgroups of samples
| Antigen detection test | ||||||||
|---|---|---|---|---|---|---|---|---|
| Positive | Negative | Sensitivity | Specificity | |||||
| Samples | RT-PCR | n | n | n | % | 95% CI | % | |
| All | Positive | 82 | 77 | 5 | 93.9 | 86.5–97.4 | 100% | |
| Negative | 45 | 0 | 45 | |||||
| Sex | Male | Positive | 44 | 43 | 1 | 97.7 | 88.2–99.6 | 100% |
| Negative | 24 | 0 | 24 | |||||
| Female | Positive | 38 | 34 | 4 | 89.5 | 75.9–95.8 | 100% | |
| Negative | 21 | 0 | 21 | |||||
| Days post symptom onset | 0–7 | Positive | 76 | 72 | 4 | 94.7 | 87.2–97.9 | 100% |
| Negative | 42 | 0 | 42 | |||||
| 8–12 | Positive | 5 | 4 | 1 | 80.0 | 37.6–96.4 | 100% | |
| Negative | 3 | 0 | 3 | |||||
| Ct values | Quartile 1–3 | Positive | 52 | 52 | 0 | 100 | 89.8–100 | |
| Quartile 4 | Positive | 18 | 13 | 5 | 72.2 | 49.1–87.5 | ||
CI, confidence interval; Ct, cycle threshold of RT-PCR.